I've done this design a couple of times before, but the balance of the completed piece wasn't quite right so I made a small modification. By scanning it and creating a mirror of the side I liked better I was able to join the two halves together--that's why the numbering system of the pieces above looks a bit strange. I also increased the size as well. Completed, this one measures at 10 1/4 inches diameter, about 26cm.
I chose to use dense yellow glass for the center of the sun along with the smaller yellow rays. The orange glass is called 'wispy', its more translucent with a little bit of white streaked into it. For the background, I chose a textured teal green colored glass that's really pretty sparkly when the sun or any background light hits it.
With the copper foil, or Tiffany method of stained glass work, all the pieces are wrapped with foil--that is except for the outer edge. Where the foiled pieces butt up to each other a bead of solder will be used to bond them together. Once one side has been soldered completely, the piece is flipped and the backside is soldered as well.
How do you measure the sun? With a tape measure, of course. Here I was measuring how much lead came, a type of lead framing I would need to wrap around the piece.
I wasn't quite sure how I wanted to finish the piece. I knew I didn't want to leave it natural with silver solder showing. And black patina applied to the metals wasn't what I wanted, either. I compromised and used both copper and black patinas. The black was applied to the lead came that wraps around the suncatcher along with the solder lines closest to the outer edge. The solder around the sun and the rays was treated with copper for a warm glow.